Blood Disorders (Exam II) Marcus's Cards Flashcards
What are the S/S of vWF disorder?
Easy bruising
epistaxis
menorrhagia
Von Willabrand Factor Disorder facts
-vWF critical role in platelet adherence/adhesion
-Most common hereditary bleeding disorders
Classifications of Inherited vonWillebrand Disease
Type I: Partial quantitative deficiency of vWF
mildest; most common; responds to DDAVP
Type IIA and IIM: Dysfunction of platelet adhesion
May respond to DDAVP
Type IIB: Increased platelet binding affinity
Thrombocytopenia with DDAVP
Type IIN: Decreased F VIII-binding affinity
often confused with hemophilia A
Type III: Severe quantitative deficiency of vWF
Rarest; most severe; usually requires factor concentrates
What would lab values be for someone with vWF deficiency?
- Normal PT & aPTT
- Bleeding time is prolonged
What are the treatments for vWF deficiency?
- Desmopressin 1st line
- Cryoprecipitate
- Factor VIII (or transfusion of specific factor)
How does DDAVP work in regards to treatment of von Willebrand deficiency??
Stimulates vWF release from endothelial cells (it’s a synthetic analogue of vasopressin)
What is the dose for DDAVP?
0.3 mcg/kg in 50 mL over 15-20 mins (Do not bolus)
What is the Peak & duration of DDAVP?
- Peak: 30mins
- Duration: 6-8hrs
What are side effects of DDAVP?
- HA
- Rubor
- hypotension
- tachycardia
- hyponatremia
- water intoxication (excessive water retention)
What is the most major side effect of DDAVP?
Hyponatremia
Someone that gets DDAVP needs to be on what?
Fluid restriction 4-6hrs before & after DDAVP
What CNS and EKG changes will you see with serum Na of 120 meq/L
CNS: Confusion and restlessness
EKG: maybe widening of QRS
What CNS and EKG changes will you see with serum Na of 115 meq/L
CNS: Somnolence and nausea
EKG: elevated ST segments and widened QRS
What CNS and EKG changes will you see with serum Na of 110 meq/L
CNS: seizures, coma
EKG: Vtach or Vfib
What blood product can be utilized for vWF disease if the patient is unresponsive to DDAVP?
Cryoprecipitate
1 unit of Cryo raises the ____ level by ___?
Fibrinogen by 50 mg/dL
What is a potential risk factor with cryoprecipitate?
- Increased risk of infection (not submitted to viral attenuation)
- Multiple donors
How is factor VIII made?
- Pool of plasma from a large number of donors.
- it does undergo viral attenuation
What does factor VIII concentrate contain?
Contains Factor VIII and vWF
When is Factor VIII given?
Preop or intraop
When should DDAVP be given prior to surgery?
60mins before Sx
Anesthesia Consideration for vWF disease
- Prior evaluation by a hematologist
- Normalization of the bleeding time and improved levels of F VIII should be confirmed before the surgery in patients
- General anesthesia is preferred
- Patients with coagulopathies undergoing neuroaxial block will have increased risk of developing a hematoma and compression of neurological structures
What things to avoid in giving anesthesia to a patient with vWF disease?
- Avoid trauma in anesthesia
- A-lines aren’t recommended
- Laryngeal trauma during intubation may cause a hematoma
- IM medication is avoided
What blood product poses an increase risk for infection? Why?
- Cryoprecipitate
- Not sent for viral attenuation
Pts with coagulopathies undergoing neuraxial anesthesia are at increased risk for what?
- Hematoma
- Nerve compression
How does heparin work?
- Thrombin inhibition: which prevents the conversion of fibrinogen to fibrin
- Antithrombin III activation
What labs are monitored with heparin? and how can we reverse it?
- PTT &/or ACT
- reversible by protamine: a positively charged polypeptide forming a stable complex neutralizing heparin
What is the mechanism of action of Coumadin?
Inhibition of vitamin K-dependent factors: II, VII, IX, X
What is the onset for Vitamin K administration?
6-8hrs
What drugs/products can be given to reverse coumadin faster than Vit K?
- Prothrombin complex concentrates
- Factor VIIa
- FFP
What is the mechanism of action for fibrinolytics (Urokinase, streptokinase & tPA)?
Convert plasminogen to plasmin, which cleaves fibrin
How do tranexamic acid (TXA), aminocaproic acid, and aprotinin work?
Inhibit conversion of plasminogen to plasmin
Treating patients who are on antiplatelet therapy
- D/C drugs on time
- platelet transfusion (if you have to operate emergently) becuase these medicaion irrversibly bind to the platelet
What is disseminated intravascular coagulopathy?
- Systemic activation of the coagulation system simultaneously leads to thrombus formation and exhaustion of platelets and coagulation factors
- Numerous underlying disorders may precipitate DIC, including trauma, amniotic fluid embolus, malignancy, sepsis (longer onset except for urosepsis), or incompatible blood transfusions
What is the best way to treat DIC?
Treat the underlying cause
What will labs show for someone in DIC?
- ↓Platelet count
- Prolonged PT, PTT & TT.
- ↑ fibrin degradation products
When is antifibrinolytic therapy given to someone in DIC?
Trick question, it shouldn’t. Can lead to catastrophic thrombotic complications
What should the treatment for DIC include?
Treatment includes blood component transfusions to replete coagulation factors and platelets consumed in the process
What is factor V?
- Protein for clotting.
Activated protein C inactivates factor V thus stopping clot growth.
What is Factor V Leiden?
Genetic mutation where Activated protein C cannot stop factor V Leiden thus excessive fibrin.
What does Activated Protein C do?
Inactivates factor V when enough fibrin has been made.
Who is usually tested for Factor V Leiden?
Pregnant women. Especially ones with unexplained late stage abortions
What anticoagulant medications could someone with Factor V Leiden be put on?
- Warfarin
- LMWH & unfractionated heparin
Anesthesia implications of Factor V Leiden
- Patients will be on anticoagulants becuase they have an increased risk of DVT or PE
Pathology of HIT
HIT describes an autoimmune-mediated drug reaction occurring in as many as 5% of patients after exposure to unfractionated heparin or (rare cases) LMWH
Thrombocytopenia occurs 5-14 days after initial therapy
What is the hallmark sign of HIT?
Plt count <100,000
thrombocytopenia
HIT results in ____ activation and potential____?
platelet; thrombosis
What is heparin replaced with when HIT is diagnosed?
Agratroban, lepirudin, or bivalirudin (direct-thrombin inhibitors)
What is Fondaparinux & when is it used?
- A synthetic Factor Xa inhibitor
- used to treat VTE in HIT (off label use)
- If possible, avoid future exposure to unfractionated heparin
